The No 3 seeded Vietnamese and Chinese pair defeated Singh Karunuday of India and Alcantara Francis Casey of the Philippines, No 4 seed, 6-4, 6-4 in 76 minutes.
It is Nam’s third international trophy after victories in the Vietnam F5 and F9 tournaments last year. In 2015 Nam and Sumit Nagal of India won the Wimbledon boys’ doubles.
Earlier in the singles event, Nam lost 4-6, 6-4, 1-6 to his partner Fajing in the quarter-finals.
Nam will return home and prepare for his next tournament at the Thailand F4 event on July 31- August 6 and the Southeast Asian Games in Malaysia in August.